Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Hyo Seong Choi is active.

Publication


Featured researches published by Hyo Seong Choi.


Lancet Oncology | 2010

Open versus laparoscopic surgery for mid or low rectal cancer after neoadjuvant chemoradiotherapy (COREAN trial): short-term outcomes of an open-label randomised controlled trial

Sung-Bum Kang; Ji Won Park; Byung-Ho Nam; Hyo Seong Choi; Duck-Woo Kim; Seok-Byung Lim; Taek-Gu Lee; Dae Yong Kim; Jae-Sung Kim; Hee Jin Chang; Hye Seung Lee; Sun Young Kim; Kyung Hae Jung; Yong Sang Hong; Jee Hyun Kim; Dae Kyung Sohn; Dae-Hyun Kim

BACKGROUND The safety and short-term efficacy of laparoscopic surgery for rectal cancer after preoperative chemoradiotherapy has not been demonstrated. The aim of the randomised Comparison of Open versus laparoscopic surgery for mid and low REctal cancer After Neoadjuvant chemoradiotherapy (COREAN) trial was to compare open surgery with laparoscopic surgery for mid or low rectal cancer after neoadjuvant chemoradiotherapy. METHODS Between April 4, 2006, and Aug 26, 2009, patients with cT3N0-2 mid or low rectal cancer without distant metastasis after preoperative chemoradiotherapy were enrolled at three tertiary-referral hospitals. Patients were randomised 1:1 to receive either open surgery (n=170) or laparoscopic surgery (n=170), stratified according to sex and preoperative chemotherapy regimen. Short-term outcomes assessed were involvement of the circumferential resection margin, macroscopic quality of the total mesorectal excision specimen, number of harvested lymph nodes, recovery of bowel function, perioperative morbidity, postoperative pain, and quality of life. Analyses were based on the intention-to-treat population. Patients continue to be followed up for the primary outcome (3-year disease-free survival). This study is registered with ClinicalTrials.gov, number NCT00470951. FINDINGS Two patients (1.2%) in the laparoscopic group were converted to open surgery, but were included in the laparoscopic group for analyses. Estimated blood loss was less in the laparoscopic group than in the open group (median 217.5 mL [150.0-400.0] in the open group vs 200.0 mL [100.0-300.0] in the laparoscopic group, p=0.006), although surgery time was longer in the laparoscopic group (mean 244.9 min [SD 75.4] vs 197.0 min [62.9], p<0.0001). Involvement of the circumferential resection margin, macroscopic quality of the total mesorectal excision specimen, number of harvested lymph nodes, and perioperative morbidity did not differ between the two groups. The laparoscopic surgery group showed earlier recovery of bowel function than the open surgery group (time to pass first flatus, median 38.5 h [23.0-53.0] vs 60.0 h [43.0-73.0], p<0.0001; time to resume a normal diet, 85.0 h [66.0-95.0] vs 93.0 h [86.0-121.0], p<0.0001; time to first defecation, 96.5 h [70.0-125.0] vs 123 h [94.0-156.0], p<0.0001). The total amount of morphine used was less in the laparoscopic group than in the open group (median 107.2 mg [80.0-150.0] vs 156.9 mg [117.0-185.2], p<0.0001). 3 months after proctectomy or ileostomy takedown, the laparoscopic group showed better physical functioning score than the open group (0.501 [n=122] vs -4.970 [n=128], p=0.0073), less fatigue (-5.659 [n=122] vs 0.098 [n=129], p=0.0206), and fewer micturition (-2.583 [n=122] vs 4.725 [n=129], p=0.0002), gastrointestinal (-0.400 [n=122] vs 4.331 [n=129], p=0.0102), and defecation problems (0.535 [n=103] vs 5.327 [n=99], p=0.0184) in repeated measures analysis of covariance, adjusted for baseline values. INTERPRETATION Laparoscopic surgery after preoperative chemoradiotherapy for mid or low rectal cancer is safe and has short-term benefits compared with open surgery; the quality of oncological resection was equivalent.


Lancet Oncology | 2014

Open versus laparoscopic surgery for mid-rectal or low-rectal cancer after neoadjuvant chemoradiotherapy (COREAN trial): survival outcomes of an open-label, non-inferiority, randomised controlled trial

Ji Won Park; Byung-Ho Nam; Sohee Kim; Sung-Bum Kang; Seok-Byung Lim; Hyo Seong Choi; Duck-Woo Kim; Hee Jin Chang; Dae Yong Kim; Kyung Hae Jung; Tae-You Kim; Gyeong Hoon Kang; Eui Kyu Chie; Sunyoung Kim; Dae Kyung Sohn; Dae-Hyun Kim; Jae-Sung Kim; Hye Seung Lee; Jee Hyun Kim

BACKGROUND Compared with open resection, laparoscopic resection of rectal cancers is associated with improved short-term outcomes, but high-level evidence showing similar long-term outcomes is scarce. We aimed to compare survival outcomes of laparoscopic surgery with open surgery for patients with mid-rectal or low-rectal cancer. METHODS The Comparison of Open versus laparoscopic surgery for mid or low REctal cancer After Neoadjuvant chemoradiotherapy (COREAN) trial was an open-label, non-inferiority, randomised controlled trial done between April 4, 2006, and Aug 26, 2009, at three centres in Korea. Patients (aged 18-80 years) with cT3N0-2M0 mid-rectal or low-rectal cancer who had received preoperative chemoradiotherapy were randomly assigned (1:1) to receive either open or laparoscopic surgery. Randomisation was stratified by sex and preoperative chemotherapy regimen. Investigators were masked to the randomisation sequence; patients and clinicians were not masked to the treatment assignments. The primary endpoint was 3 year disease-free survival, with a non-inferiority margin of 15%. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00470951. FINDINGS We randomly assigned 340 patients to receive either open surgery (n=170) or laparoscopic surgery (n=170). 3 year disease-free survival was 72·5% (95% CI 65·0-78·6) for the open surgery group and 79·2% (72·3-84·6) for the laparoscopic surgery group, with a difference that was lower than the prespecified non-inferiority margin (-6·7%, 95% CI -15·8 to 2·4; p<0·0001). 25 (15%) patients died in the open group and 20 (12%) died in the laparoscopic group. No deaths were treatment related. INTERPRETATION Our results show that laparoscopic resection for locally advanced rectal cancer after preoperative chemoradiotherapy provides similar outcomes for disease-free survival as open resection, thus justifying its use. FUNDING National Cancer Center, South Korea.


Annals of Surgery | 2008

Optimal surgery time after preoperative chemoradiotherapy for locally advanced rectal cancers.

Seok-Byung Lim; Hyo Seong Choi; Dae Yong Kim; Kyung Hae Jung; Yong Sang Hong; Hee Jin Chang; Jae-Gahb Park

Objective:To evaluate the effect of the time interval between chemoradiotherapy (CRT) and surgery on CRT response and surgical outcomes. Summary Background Data:Although preoperative CRT is a standard component of multimodal treatment for locally advanced rectal cancers, the optimal time for surgery after CRT has yet to be established. This study analyzed outcomes in 397 prospectively enrolled patients with locally advanced rectal cancer who underwent fractionated CRT involving 50.4 Gy radiotherapy followed by surgical resection between 4 and 8 weeks later. Methods:Patients were divided into 2 groups according to the time that elapsed between CRT and surgery: group A (28–41 day interval) and group B (42–56 day interval). CRT responses and surgical outcomes were analyzed. Results:Of the 397 patients, 217 (54.7%) were in group A and 180 (45.3%) in group B. The 2 groups were similar in terms of pretreatment characteristics other than a slight difference in mean age (A: 55.3 years vs. B: 57.5 years, P = 0.042). Analysis of CRT responses showed that the 2 groups were similar in terms of T-level downstaging rate (A: 47.5% vs. B: 44.4%, P = 0.548), volume reduction rate (A: 34.6% vs. B: 34.2%, P = 0.870) and complete response rate (A: 13.8% vs. B: 15.0%, P = 0.740). Analysis of surgical outcomes showed that the 2 groups were also similar in terms of sphincter-preservation rate (A: 83.9% vs. B: 82.2%, P = 0.688) and anastomosis-related complication rate (A: 5.5% vs. B: 3.9%, P = 0.453). The median follow-up period was 31 months (range, 5–63), and both groups showed similar local recurrence-free survival rates (P = 0.1165). Conclusion:The present findings suggest that compared with a 4 to 6 week interval, delaying surgery for 6 to 8 weeks after completion of fractionated radiotherapy with concurrent chemotherapy does not improve CRT response or the sphincter-preservation rate, and does not decrease morbidity or local recurrence.


Annals of Surgery | 2010

Influence of preoperative chemoradiotherapy on the number of lymph nodes retrieved in rectal cancer.

Yun Hyung Ha; Seok-Byung Lim; Hyo Seong Choi; Yong Sang Hong; Hee Jin Chang; Dae Yong Kim; Kyung Hae Jung; Jae-Gahb Park

Objective:To evaluate the relation of preoperative chemoradiotherapy to the number of lymph nodes retrieved in curative intent surgery for rectal cancer. Summary Background Data:Current guidelines recommend evaluation of least 12 to 14 lymph nodes in rectal cancer. It is well known that lymph nodes retrieval is affected by many factors. Methods:This was a retrospective study of 615 patients who underwent curative intent surgery for primary rectal cancer. Preoperative chemoradiotherapy involving 50.4 Gy fractionated radiotherapy and concurrent chemotherapy was performed in patients with locally advanced rectal cancer (clinically T3 or T4). We explored associations between the number of lymph nodes retrieved in the pathologic specimen and patient demographics (age, gender, body mass index [BMI]), treatment (surgeon, sphincter-saving, preoperative chemoradiotherapy), and tumor-related variables (location, stage, histology). After adjustment for other factors, we compared the mean number of obtained lymph nodes between patients treated with preoperative chemoradiotherapy and those treated without preoperative chemoradiotherapy. Results:Univariate analysis demonstrated that age, BMI, preoperative chemoradiotherapy, location, and stage significantly related the number of lymph nodes retrieved. Multivariate analysis revealed age, BMI, preoperative chemoradiotherapy, and stage as independent factors influencing the number of lymph nodes retrieved. The mean number of lymph nodes adjusted for age, BMI, and stage was significantly lower in patients treated with preoperative chemoradiotherapy than in those treated without preoperative chemoradiotherapy (14.5 vs. 21.5, P < 0.001). The reduction rate by preoperative chemoradiotherapy was 32.6% (7/21.5). In patients who underwent preoperative chemoradiotherapy, advanced age (P < 0.001) and high BMI (P = 0.037) were associated with decreased number of retrieved lymph nodes. Conclusions:Preoperative chemoradiotherapy significantly decreased the number of retrieved lymph nodes by approximately 33%. Therefore, the recommended number of retrieved lymph nodes should be adjusted when rectal cancer is treated with preoperative chemoradiotherapy.


International Journal of Radiation Oncology Biology Physics | 2010

Pathologic Nodal Classification Is the Most Discriminating Prognostic Factor for Disease-Free Survival in Rectal Cancer Patients Treated With Preoperative Chemoradiotherapy and Curative Resection

Tae Hyun Kim; Hee Jin Chang; Dae Yong Kim; Kyung Hae Jung; Yong Sang Hong; Sun Young Kim; Ji Won Park; Seok-Byung Lim; Hyo Seong Choi

PURPOSE We retrospectively evaluated the effects of clinical and pathologic factors on disease-free survival (DFS) with the aim of identifying the most discriminating factor predicting DFS in rectal cancer patients treated with preoperative chemoradiotherapy (CRT) and curative resection. METHODS AND MATERIALS The study involved 420 patients who underwent preoperative CRT and curative resection between August 2001 and October 2006. Gender, age, distance from the anal verge, histologic type, histologic grade, pretreatment carcinoembryonic antigen (CEA) level, cT, cN, cStage, circumferential resection margin, type of surgery, preoperative chemotherapy, adjuvant chemotherapy, ypT, ypN, ypStage, and tumor regression grade (TRG) were analyzed to identify prognostic factors associated with DFS. To compare the discriminatory prognostic ability of four tumor response-related pathologic factors (ypT, ypN, ypStage, and TRG), the Akaike information criteria were calculated. RESULTS The 5-year DFS rate was 75.4%. On univariate analysis, distance from the anal verge, histologic type, histologic grade, pretreatment CEA level, cT, circumferential resection margin, type of surgery, preoperative chemotherapeutic regimen, ypT, ypN, ypStage, and TRG were significantly associated with DFS. Multivariate analysis showed that the four parameters ypT, ypN, ypStage, and TRG were, consistently, significant prognostic factors for DFS. The ypN showed the lowest Akaike information criteria value for DFS, followed by ypStage, ypT, and TRG, in that order. CONCLUSION In our study, ypT, ypN, ypStage, and TRG were important prognostic factors for DFS, and ypN was the most discriminating factor.


International Journal of Radiation Oncology Biology Physics | 2010

Tumor Volume Reduction Rate Measured by Magnetic Resonance Volumetry Correlated With Pathologic Tumor Response of Preoperative Chemoradiotherapy for Rectal Cancer

Seung-Gu Yeo; Dae Yong Kim; Tae Hyun Kim; Kyung Hae Jung; Yong Sang Hong; Hee Jin Chang; Ji Won Park; Seok-Byung Lim; Hyo Seong Choi

PURPOSE To determine whether the tumor volume reduction rate (TVRR) measured using three-dimensional region-of-interest magnetic resonance volumetry correlates with the pathologic tumor response after preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer. METHODS AND MATERIALS The study included 405 patients with locally advanced rectal cancer (cT3-T4) who had undergone preoperative CRT and radical proctectomy. The tumor volume was measured using three-dimensional region-of-interest magnetic resonance volumetry before and after CRT but before surgery. We analyzed the correlation between the TVRR and the pathologic tumor response in terms of downstaging and tumor regression grade (TRG). Downstaging was defined as ypStage 0-I (ypT0-T2N0M0), and the TRG proposed by Dworak et al. was used. RESULTS The mean TVRR was 65.0% +/- 22.3%. Downstaging and complete regression occurred in 167 (41.2%) and 58 (14.3%) patients, respectively. The TVRRs according to ypT classification (ypT0-T2 vs. ypT3-T4), ypN classification (ypN0 vs. ypN1-N2), downstaging (ypStage 0-I vs. ypStage II-III), good regression (TRG 3-4 vs. TRG 1-2), and complete regression (TRG 4 vs. TRG 1-3) were all significantly different (p <.05). When the TVRR was categorized into three groups (<60%, 60-80%, and >80%), the rates of ypT0-T2, ypN0, downstaging, and good regression were all significantly greater for patients with a TVRR of >or=60%, as was the complete regression rate for patients with a TVRR >80% (p <.05). CONCLUSION The TVRR measured using three-dimensional region-of-interest magnetic resonance volumetry correlated significantly with the pathologic tumor response in terms of downstaging and TRG after preoperative CRT for locally advanced rectal cancer.


Surgical Endoscopy and Other Interventional Techniques | 2008

The usefulness of preoperative colonoscopic tattooing using a saline test injection method with prepackaged sterile India ink for localization in laparoscopic colorectal surgery

Ji Won Park; Dae Kyung Sohn; Chang Won Hong; Kyung Su Han; Dong Hyun Choi; Hee Jin Chang; S.-B. Lim; Hyo Seong Choi; S.-Y. Jeong

BackgroundLaparoscopic surgery for colorectal neoplasm requires precise tumor localization. The authors have assessed the safety and efficacy of colonoscopic tattooing using a saline test injection method with prepackaged sterile India ink for tumor localization in laparoscopic colorectal surgery.MethodsBetween July 2004 and January 2007, 63 patients underwent colonoscopic tattooing using prepackaged sterile India ink before laparoscopic surgery of colorectal tumors. Patient medical records and operation videos were retrospectively assessed.ResultsTattoos were visualized intraoperatively in 62 (98.4%) of the 63 patients, and colorectal tumors were accurately localized in 61 patients (96.8%). In one patient, the tattoo could not be detected, whereas in another patient, it was visualized but the serosal surface of the rectosigmoid colon was stained diffusely. Both of these patients underwent intraoperative colonoscopy. Localized leakages of ink were identified in six patients (9.5%) during surgery. However, five of these patients had no symptoms, and the sixth patient, who underwent polypectomy and tattooing simultaneously, felt mild chilling without fever or abdominal pain.ConclusionsPreoperative colonoscopic tattooing using a saline test injection method with prepackaged sterile India ink is a safe and effective method for tumor localization in laparoscopic colorectal surgery.


Journal of Clinical Pathology | 2006

Histopathological risk factors for lymph node metastasis in submucosal invasive colorectal carcinoma of pedunculated or semipedunculated type.

Dae Kyung Sohn; Hee Jin Chang; Ji Won Park; Dong Hyun Choi; Kyung Su Han; Chang Won Hong; Kyung Hae Jung; Dae Yong Kim; Seok-Byung Lim; Hyo Seong Choi

Aims: To evaluate the histopathological risk factors for lymph node metastasis in cases of pedunculated or semipedunculated submucosal invasive colorectal carcinoma (SICC). Methods: A total of 48 patients with non-sessile SICC who underwent systematic lymph node dissection were included. Tumour size, histological grade, angiolymphatic invasion, tumour budding, dedifferentiation, objective submucosal invasion depth from the identified muscularis mucosa, relative invasion depth of the submucosal layer, and depth of stalk invasion were investigated histopathologically. Results: Lymph node metastasis was observed in seven cases (14.6%). Univariate analysis showed angiolymphatic invasion and tumour budding to be significantly associated with lymph node metastasis. Multivariate analysis showed that tumour budding was the only independent factor associated with lymph node metastasis in cases of non-sessile SICC. Conclusions: Results indicate that tumour budding is a useful risk factor for predicting lymph node metastasis in cases of pedunculated or semipedunculated SICC.


International Journal of Radiation Oncology Biology Physics | 2009

Carcinoembryonic antigen as a predictor of pathologic response and a prognostic factor in locally advanced rectal cancer patients treated with preoperative chemoradiotherapy and surgery.

Ji Won Park; Seok-Byung Lim; Dae Yong Kim; Kyung Hae Jung; Yong Sang Hong; Hee Jin Chang; Hyo Seong Choi

PURPOSE To evaluate the role of serum carcinoembryonic antigen (CEA) as a predictor of response to preoperative chemoradiotherapy (CRT) and prognostic factor for rectal cancer. MATERIALS AND METHODS The study retrospectively evaluated 352 locally advanced rectal cancer patients who underwent preoperative CRT followed by surgery. Serum CEA levels were determined before CRT administration (pre-CRT CEA) and before surgery (post-CRT CEA). Correlations between pre-CRT CEA levels and rates of good response (Tumor regression grade 3/4) were explored. Patients were categorized into three CEA groups according to their pre-/post-CRT CEA levels (ng/mL) (Group A: pre-CRT CEA <or= 3; B: pre-CRT CEA >3, post-CRT CEA <or=3; C: pre- and post-CRT CEA >3 ng/mL), and their oncologic outcomes were compared. RESULTS Of 352 patients, good responses were achieved in 94 patients (26.7%). The rates of good response decreased significantly as the pre-CRT CEA levels became more elevated (CEA [ng/mL]: <or=3, 36.4%; 3-6, 23.6%; 6-9, 15.6%; >9, 7.8%; p < 0.001). The rates of good response were significantly higher in Group A than in Groups B and C (36.4% vs. 17.3% and 14.3%, respectively; p < 0.001). The 3-year disease-free survival rate was significantly better in Groups A and B than in Group C (82% and 79% vs. 57%, respectively; p = 0.005); the CEA grouping was identified as an independent prognostic factor (p = 0.025). CONCLUSIONS In locally advanced rectal cancer patients, CEA levels could be of clinical value as a predictor of response to preoperative CRT and as an independent prognostic factor after preoperative CRT and curative surgery.


Diseases of The Colon & Rectum | 2009

Indications for subsequent surgery after endoscopic resection of submucosally invasive colorectal carcinomas: a prospective cohort study.

Dong Hyun Choi; Dae Kyung Sohn; Hee Jin Chang; Seok-Byung Lim; Hyo Seong Choi

PURPOSE: This study explored predictive factors that affected oncologic outcomes after surgical resection or follow-up without surgery in patients with submucosally invasive colorectal carcinomas after endoscopic resection. METHODS: Oncologic outcomes in terms of lymph node metastasis or tumor recurrence were assessed according to resection margin, histology, and depth of invasion. RESULTS: Eighty-seven patients with submucosally invasive colorectal carcinomas after endoscopic resection were followed prospectively. Fifty-seven (65.5 percent) patients had risk factors of deep submucosal invasion and/or unfavorable histology. Among them, 30 underwent radical resection, and 6 patients had lymph node metastases. Twenty patients with risk factors were closely followed up and 3 recurrent carcinomas were detected. Ultimately, 9 of 57 high-risk patients (15.8 percent) exhibited lymph node metastasis or tumor recurrence. Among 30 patients without risk factors, none had lymph node metastasis or recurrent carcinoma. Univariate analysis showed that tumor budding (P = 0.003) and venous invasion (P = 0.021) were factors for lymph node metastasis. In multivariate analysis, only tumor budding was an independent predictor of lymph node metastasis (P = 0.026). CONCLUSIONS: Approximately 16 percent of patients with submucosally invasive colorectal carcinoma and risk factors benefited from subsequent surgery. Tumor budding was the most significant factor for lymph node metastasis. Observation would be appropriate for patients without risk factors after endoscopic resection.

Collaboration


Dive into the Hyo Seong Choi's collaboration.

Top Co-Authors

Avatar

Hee Jin Chang

Seoul National University

View shared research outputs
Top Co-Authors

Avatar

Ji Won Park

Seoul National University

View shared research outputs
Top Co-Authors

Avatar

Dae Yong Kim

Sungkyunkwan University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Dae Kyung Sohn

Seoul National University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Chang Won Hong

Seoul National University

View shared research outputs
Top Co-Authors

Avatar

Jae-Gahb Park

Seoul National University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge